I recently tried to use NonlinearFit.m and discovered a bug in it. When
you try to give it upper and lower limits on the parameters NonlinearFit
fails. The tech people sent me a revised and fixed version. Please don't
ask me for the fix, I'm afraid of getting swamped with requests. The
email address for support is:
student-support at wri.com.
I'm sure there's a regular support line as well. They ask that you
include your MMA license number when you correspond with them.
Good luck,
Mike Helgerud
PS My version of MMA is 2.2.1
--
Mike Helgerud
Geophysics Department
Stanford University
Stanford, CA 94305
415-723-0253